Chemotherapy-induced anemia: the story of darbepoetin alfa

BACKGROUND

Prior to the approval of the first erythropoiesis-stimulating agent (ESA) in the early 1990s, red blood cell transfusions were the primary means of treating severe chemotherapy-induced anemia (CIA), with little recourse for those with more mild forms of the condition. The introduction of the ESAs allowed treatment of mild-to-moderate CIA in patients with cancer. It has been a decade since darbepoetin alfa (DA), a second-generation ESA with a longer half-life, became available to patients with CIA.

OBJECTIVE AND METHODS

We present a review of studies on DA in CIA, from its development through to the present day. Medline was searched for randomized clinical trials on DA. Additional trials and meta-analyses on ESAs were incorporated into this review when relevant.

RESULTS

The first publications on DA generally focused on optimal dosing, efficacy and tolerability. In these, it was shown that DA is an effective and well tolerated treatment option to achieve hematopoietic response, regardless of dosing interval. Subsequently, the focus shifted towards meta-analyses on survival data of all ESAs. These reported conflicting results regarding mortality and/or disease progression. However, guidelines for ESA use were updated and, when followed, these make ESAs a well tolerated and effective tool for managing CIA.

CONCLUSIONS

As the past decade has broadened our knowledge on the benefits and risks of CIA management, continued high-quality studies will help to optimize treatment with ESAs in order to maximize quality of life for these patients. The limitation of a literature review of this nature is the complete reliance on previously published research and the availability of these studies using the methodology outlined above.

A final analysis from the CHOICE study examining darbepoetin alfa use for chemotherapy-induced anaemia in current European clinical practice

OBJECTIVES

The CHOICE study was a prospective, multicentre, observational study designed to assess the level of adherence in current clinical practice to the European product label and the EORTC guidelines for the treatment of chemotherapy-induced anaemia with darbepoetin alfa (DA).

METHODS

Hb levels and red blood cell (RBC) transfusion requirements were evaluated among 1900 patients with solid tumours in 11 European countries. The primary outcome measure was the proportion of patients with a target Hb level of ≥10-≤12 g/dL after 9 weeks' DA treatment.

RESULTS

The full analysis set (FAS) comprised 1887 patients (mean ± SD age 62.4 ± 11.4 years) divided into categories by baseline Hb < 9 g/dL (n = 281); 9-<10 g/dL (n = 770); 10-<11 g/dL (n = 695); ≥11 g/dL (n = 114). The proportion of patients who remained on the study at week 9 achieving the target Hb level was 37% (n = 60), 48% (n = 217), 54% (n = 210) and 38% (n = 23) in the subgroups with a baseline Hb level of <9 g/dL, 9-<10 g/dL, 10-<11 g/dL and ≥11 g/dL, respectively. In the <9 g/dL, 9-<10 g/dL, 10-<11 g/dL and ≥11 g/dL subgroups of the FAS, the number of patients maintaining Hb levels ≥10 g/dL after their first achievement of an Hb value of 10 g/dL was 95 (34%), 372 (48%), 476 (68%) and 87 (76%), respectively. The Kaplan-Meier percentages of patients who required an RBC transfusion from week 5 until end of treatment period were: 29%, 20%, 12% and 17% in the <9 g/dL, 9-<10 g/dL, 10-<11 g/dL and ≥11 g/dL subgroups, respectively. Kaplan-Meier percentages of patients reaching an Hb level of >13 g/dL were 10%, 9%, 21% and 29%, respectively. Potential bias could not be excluded due to the study's observational nature.

CONCLUSIONS

DA initiation and target Hb ranges adhered to current guidelines in the majority of patients. Furthermore, this study demonstrates faster achievement of the target range and reduced transfusion requirements are associated with initiation of DA at Hb levels of 9-<10 g/dL and 10-<11 g/dL rather than <9 g/dL.